(A) Leaf morphology of wild type, cao/ch1, and 35S::MIM156 cao/ch1 plants under long day conditions. The leaves from 15-day-old plants were detached and scanned. The numbers indicate leaf positions. (B and C) The length-to-width ratio of the blade (B) and the appearance of the first abaxial trichome (C). n=12. (D) Expression of miR156 during development. Wild type plants and cao/ch1 mutants were collected at 7, 9, or 12 days after germination under long day conditions. (E) Expression of miR156, pri-MIR156A, and pri-MIR156C. Five-day-old wild type and cao/ch1 mutants in 1/2 Murashige and Skoog (MS) liquid media were treated with 50 mM glucose or mannitol for 1 day. The expression levels in the mannitol-treated wild type or cao/ch1 were set to 1. The treatment was started at Zeitgeber time 12. **Significant difference from wild type, Student t-test, p<0.001. Error bars indicate SE.